The present invention generally relates to combines or harvesters that pull an integrated, often powered and steerable, grain trailer for extra storage capacity, and more particularly to a simple conversion thereof into an articulated harvester. For present purposes the term “harvester” will be used to include, inter alia, combines, corn pickers, harvesters, and like equipment that pick, harvest, or otherwise process grains in field. Often the term “combine” will be used herein; however, such use is by way of illustration and not by way of limitation.
Modern grain combines, such as are used to harvest corn, wheat, soybeans, etc., and corn pickers, have significantly increased their throughput capability. These increases have resulted from improvements such as wider cutting heads and increased number of row units per machine in the case of row crops such as corn. The threshing and grain separating capacity of the machines has increased in parallel by building larger machines with higher horsepower engines.
Concomitant therewith, the number of acres in the average North American farm has increased dramatically with crop fields becoming larger and longer. Fields with a row length of one-half mile have become quite common.
The result of these simultaneous trends is that the amount of harvested crop or clean grain produced in one round or two lengths of the field has increased dramatically. The harvested grain must be carried along by the harvesting system until the end of the field is reached where it is transferred into a bulk transportation vehicle such as a truck (tractor-trailer or semi) or wagon. Combines have an onboard grain hopper in which to store the harvested grain until the end of the field has been reached. Seed corn pickers typically pull a trailer or wagon, or a truck is driven along side them to receive the grain.
Due to increased combine throughput and long fields, virtually no combine commercially available today has sufficient capacity in its on-board hopper to store the corn harvested during one round of an 80 acre field or a field which is one-half mile in length with the crop yields typically found in the U.S. corn belt. The on-board primary storage hoppers are limited in capacity by the physical size of the machine and the total weight of the combine with a full hopper, which can be carried on 2 axles or 2 tracks in some cases.
Farmers and farm equipment manufacturers have addressed this problem by developing intermediate transport grain carts or trailers, which are pulled by a separate tractor and operator. The grain cart/tractor combination is stationed at the opposite end of the field from the road transport (bulk storage) vehicle or along the length of the field to receive the grain from the combine when its primary hopper is full and before the combine reaches the end of the field where the road transport vehicle is located. The traditional grain cart has self-unloading capability usually in the form of an auger, conveyor, or side hydraulic dump mechanism, which receives power from the tractor. The grain cart/tractor combination typically carries the grain to the end of the field and loads it into the road transport vehicle, such as a semi-truck. Examples of such grain wagons can be found in U.S. Pat. Nos. 5,013,208, 5,340,265, and 5,409,344.
Grain cart capacities typically vary from 400 bushels to 1000 bushels. Therefore, a loaded grain cart and pulling tractor may weigh as much as 90,000 pounds. Repeated trips across the field by this large vehicle combination can produce additional soil compaction, particularly in wet conditions, which reduces future crop yields. This method of intermediate storage and movement of grain with the field incrementally adds one operator and significant capital cost to the harvesting process.
In the field of trailers or wagons that are towed by a farm tractor or over-the-road tractor-trailers (so-called “semis”), U.S. Pat. No. 2,667,028 shows a towable combine with an attached grain cart. U.S. Pat. No. 4,460,193 shows a pull type swather assembly, which can be crabbed. U.S. Pat. No. 4,359,854 shows a tractor drawn combine, which also can be crabbed. U.S. Pat. No. 5,412,929 shows the ability to steer a pair of rakes being towed by a tractor. U.S. Pat. No. 5,579,228 shows a servo steering control system for a non-powered trailer that includes forward and backward motion. U.S. Pat. No. 5,209,320 shows an articulated crop pesticide sprayer adapted to be pulled. U.S. Pat. No. 4,740,006 proposes to retrofit existing tractor-trailers with a remote-control steering system. Finally, U.S. Pat. No. 5,329,451 proposes a steerable trailer and steering apparatus, which includes a servo control.
A significant advance in grain carts is disclosed in U.S. Pat. No. 5,904,365. Disclosed is a powered towing vehicle having steering wheels and a wheeled trailer is connected to the vehicle for its towing. The wheels of the trailer are connected to a source of power for generating forward and rearward movement of the trailer. These wheels also are connected to a source of power for turning such wheels in order to steer the trailer. These wheels further are connected to a sensor to sense the position of the trailer wheels as they are being steered. The steering wheels of the towing vehicle also are connected to a sensor to sense the position of the vehicle wheels as they are being steered. The trailer steering wheel sensor is displayed to an operator of the vehicle so that the vehicle operator knows the relative position of each of the steering wheels. The trailer steering power source is connected to the vehicle so that an operator of the vehicle can remotely steer the wheels of the trailer. Unloading of the grain takes place separately from both the combine hopper and from the grain cart.
An improved grain handling assembly for a combine and grain cart combination is disclosed in application Ser. No. 10/247,249, filed on Sep. 19, 2002, the disclosure thereof being expressly incorporated herein by reference.
Articulated combines can be found in U.S. Pat. Nos. 6,012,272, 6,125,618, 6,339,917, and subsequent divisional patents therefrom. Implementation of these articulated combines commercially requires new tooling and market acceptance; yet, the advantages of articulated vehicles is well known. The present invention, then, is addressed to retrofitting harvester/grain cart assemblies and converting them into articulated harvesters with the advantages attendant therewith. The present invention also is addressed to manufacturing (from scratch) such an articulated harvester as an original equipment item.